curl --request POST \
--url https://api.rivermarkets.com/v1/rfqs \
--header 'Content-Type: application/json' \
--header 'X-River-Key-Id: <api-key>' \
--header 'X-River-Signature: <api-key>' \
--header 'X-River-Timestamp: <api-key>' \
--data '
{
"subaccount_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
"river_id": 123,
"contracts": 2,
"contracts_fp": 1,
"target_cost_dollars": 1,
"obscure_creator_id": true
}
'import requests
url = "https://api.rivermarkets.com/v1/rfqs"
payload = {
"subaccount_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
"river_id": 123,
"contracts": 2,
"contracts_fp": 1,
"target_cost_dollars": 1,
"obscure_creator_id": True
}
headers = {
"X-River-Key-Id": "<api-key>",
"X-River-Timestamp": "<api-key>",
"X-River-Signature": "<api-key>",
"Content-Type": "application/json"
}
response = requests.post(url, json=payload, headers=headers)
print(response.text)const options = {
method: 'POST',
headers: {
'X-River-Key-Id': '<api-key>',
'X-River-Timestamp': '<api-key>',
'X-River-Signature': '<api-key>',
'Content-Type': 'application/json'
},
body: JSON.stringify({
subaccount_id: '3c90c3cc-0d44-4b50-8888-8dd25736052a',
river_id: 123,
contracts: 2,
contracts_fp: 1,
target_cost_dollars: 1,
obscure_creator_id: true
})
};
fetch('https://api.rivermarkets.com/v1/rfqs', options)
.then(res => res.json())
.then(res => console.log(res))
.catch(err => console.error(err));<?php
$curl = curl_init();
curl_setopt_array($curl, [
CURLOPT_URL => "https://api.rivermarkets.com/v1/rfqs",
CURLOPT_RETURNTRANSFER => true,
CURLOPT_ENCODING => "",
CURLOPT_MAXREDIRS => 10,
CURLOPT_TIMEOUT => 30,
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
CURLOPT_CUSTOMREQUEST => "POST",
CURLOPT_POSTFIELDS => json_encode([
'subaccount_id' => '3c90c3cc-0d44-4b50-8888-8dd25736052a',
'river_id' => 123,
'contracts' => 2,
'contracts_fp' => 1,
'target_cost_dollars' => 1,
'obscure_creator_id' => true
]),
CURLOPT_HTTPHEADER => [
"Content-Type: application/json",
"X-River-Key-Id: <api-key>",
"X-River-Signature: <api-key>",
"X-River-Timestamp: <api-key>"
],
]);
$response = curl_exec($curl);
$err = curl_error($curl);
curl_close($curl);
if ($err) {
echo "cURL Error #:" . $err;
} else {
echo $response;
}package main
import (
"fmt"
"strings"
"net/http"
"io"
)
func main() {
url := "https://api.rivermarkets.com/v1/rfqs"
payload := strings.NewReader("{\n \"subaccount_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n \"river_id\": 123,\n \"contracts\": 2,\n \"contracts_fp\": 1,\n \"target_cost_dollars\": 1,\n \"obscure_creator_id\": true\n}")
req, _ := http.NewRequest("POST", url, payload)
req.Header.Add("X-River-Key-Id", "<api-key>")
req.Header.Add("X-River-Timestamp", "<api-key>")
req.Header.Add("X-River-Signature", "<api-key>")
req.Header.Add("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
body, _ := io.ReadAll(res.Body)
fmt.Println(string(body))
}HttpResponse<String> response = Unirest.post("https://api.rivermarkets.com/v1/rfqs")
.header("X-River-Key-Id", "<api-key>")
.header("X-River-Timestamp", "<api-key>")
.header("X-River-Signature", "<api-key>")
.header("Content-Type", "application/json")
.body("{\n \"subaccount_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n \"river_id\": 123,\n \"contracts\": 2,\n \"contracts_fp\": 1,\n \"target_cost_dollars\": 1,\n \"obscure_creator_id\": true\n}")
.asString();require 'uri'
require 'net/http'
url = URI("https://api.rivermarkets.com/v1/rfqs")
http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true
request = Net::HTTP::Post.new(url)
request["X-River-Key-Id"] = '<api-key>'
request["X-River-Timestamp"] = '<api-key>'
request["X-River-Signature"] = '<api-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n \"subaccount_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n \"river_id\": 123,\n \"contracts\": 2,\n \"contracts_fp\": 1,\n \"target_cost_dollars\": 1,\n \"obscure_creator_id\": true\n}"
response = http.request(request)
puts response.read_body{
"river_rfq_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
"exchange_rfq_id": "<string>"
}{
"detail": [
{
"loc": [
"<string>"
],
"msg": "<string>",
"type": "<string>",
"input": "<unknown>",
"ctx": {}
}
]
}Create Rfq
Post an RFQ on a River market and get its River id, the handle for the other RFQ calls. Makers answer with quotes; nothing trades until you accept one. Kalshi RFQs are sized in contracts with an optional target cost; Polymarket US RFQs in contracts or in dollars. Combos come from POST /v1/parlays/build.
curl --request POST \
--url https://api.rivermarkets.com/v1/rfqs \
--header 'Content-Type: application/json' \
--header 'X-River-Key-Id: <api-key>' \
--header 'X-River-Signature: <api-key>' \
--header 'X-River-Timestamp: <api-key>' \
--data '
{
"subaccount_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
"river_id": 123,
"contracts": 2,
"contracts_fp": 1,
"target_cost_dollars": 1,
"obscure_creator_id": true
}
'import requests
url = "https://api.rivermarkets.com/v1/rfqs"
payload = {
"subaccount_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
"river_id": 123,
"contracts": 2,
"contracts_fp": 1,
"target_cost_dollars": 1,
"obscure_creator_id": True
}
headers = {
"X-River-Key-Id": "<api-key>",
"X-River-Timestamp": "<api-key>",
"X-River-Signature": "<api-key>",
"Content-Type": "application/json"
}
response = requests.post(url, json=payload, headers=headers)
print(response.text)const options = {
method: 'POST',
headers: {
'X-River-Key-Id': '<api-key>',
'X-River-Timestamp': '<api-key>',
'X-River-Signature': '<api-key>',
'Content-Type': 'application/json'
},
body: JSON.stringify({
subaccount_id: '3c90c3cc-0d44-4b50-8888-8dd25736052a',
river_id: 123,
contracts: 2,
contracts_fp: 1,
target_cost_dollars: 1,
obscure_creator_id: true
})
};
fetch('https://api.rivermarkets.com/v1/rfqs', options)
.then(res => res.json())
.then(res => console.log(res))
.catch(err => console.error(err));<?php
$curl = curl_init();
curl_setopt_array($curl, [
CURLOPT_URL => "https://api.rivermarkets.com/v1/rfqs",
CURLOPT_RETURNTRANSFER => true,
CURLOPT_ENCODING => "",
CURLOPT_MAXREDIRS => 10,
CURLOPT_TIMEOUT => 30,
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
CURLOPT_CUSTOMREQUEST => "POST",
CURLOPT_POSTFIELDS => json_encode([
'subaccount_id' => '3c90c3cc-0d44-4b50-8888-8dd25736052a',
'river_id' => 123,
'contracts' => 2,
'contracts_fp' => 1,
'target_cost_dollars' => 1,
'obscure_creator_id' => true
]),
CURLOPT_HTTPHEADER => [
"Content-Type: application/json",
"X-River-Key-Id: <api-key>",
"X-River-Signature: <api-key>",
"X-River-Timestamp: <api-key>"
],
]);
$response = curl_exec($curl);
$err = curl_error($curl);
curl_close($curl);
if ($err) {
echo "cURL Error #:" . $err;
} else {
echo $response;
}package main
import (
"fmt"
"strings"
"net/http"
"io"
)
func main() {
url := "https://api.rivermarkets.com/v1/rfqs"
payload := strings.NewReader("{\n \"subaccount_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n \"river_id\": 123,\n \"contracts\": 2,\n \"contracts_fp\": 1,\n \"target_cost_dollars\": 1,\n \"obscure_creator_id\": true\n}")
req, _ := http.NewRequest("POST", url, payload)
req.Header.Add("X-River-Key-Id", "<api-key>")
req.Header.Add("X-River-Timestamp", "<api-key>")
req.Header.Add("X-River-Signature", "<api-key>")
req.Header.Add("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
body, _ := io.ReadAll(res.Body)
fmt.Println(string(body))
}HttpResponse<String> response = Unirest.post("https://api.rivermarkets.com/v1/rfqs")
.header("X-River-Key-Id", "<api-key>")
.header("X-River-Timestamp", "<api-key>")
.header("X-River-Signature", "<api-key>")
.header("Content-Type", "application/json")
.body("{\n \"subaccount_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n \"river_id\": 123,\n \"contracts\": 2,\n \"contracts_fp\": 1,\n \"target_cost_dollars\": 1,\n \"obscure_creator_id\": true\n}")
.asString();require 'uri'
require 'net/http'
url = URI("https://api.rivermarkets.com/v1/rfqs")
http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true
request = Net::HTTP::Post.new(url)
request["X-River-Key-Id"] = '<api-key>'
request["X-River-Timestamp"] = '<api-key>'
request["X-River-Signature"] = '<api-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n \"subaccount_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n \"river_id\": 123,\n \"contracts\": 2,\n \"contracts_fp\": 1,\n \"target_cost_dollars\": 1,\n \"obscure_creator_id\": true\n}"
response = http.request(request)
puts response.read_body{
"river_rfq_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
"exchange_rfq_id": "<string>"
}{
"detail": [
{
"loc": [
"<string>"
],
"msg": "<string>",
"type": "<string>",
"input": "<unknown>",
"ctx": {}
}
]
}Authorizations
UUID of your API key (from Settings → API Keys).
Current unix milliseconds (unix seconds also accepted). Must be within 30s of server time.
Base64 Ed25519 signature over the canonical request: METHOD\nPATH\nSORTED_QUERY\nTIMESTAMP\nSHA256(body) hex. See /api-reference/authentication for the full recipe.
Body
Non-custodial subaccount to post the RFQ under
The market to request quotes on: a single market, or a combo from POST /v1/parlays/build. The exchange follows from the market.
Whole-contract size. Provide either contracts or contracts_fp.
x >= 1Fixed-point contract size for fractional sizing.
x > 0Total target cost in USD. Kalshi: optional alongside contracts. Polymarket US: the size itself, instead of contracts.
x >= 0Kalshi only: hide your creator ID from makers until a quote executes.

